Method of and arrangement for connecting braun tubes



Oct. 5, 1937. K. SCHLESINGER 2,094,676

METHOD OF AND ARRANGEMENT FOR CONNECTING 'BRAUN TUBES Filed July 17, 1934 WWW Patented Oct. 5, 1937 a v UNHTED STATES PATENT OFFICE METHOD OF AND ARRANGEMENT FOR CONNECTING BRAUN TUBES Kurt Schlesinger, Berlin, Germany Application July 17, 1934, Serial No. 735,602 In Germany July 19, 1933 5 Claims. (Cl. 25027) In the hitherto known and more particularly metallic coatings. The arm I3 is conductively mains-operated arrangements with Braun connected withthe point IS in Fig. 1 and the tubes, in which the negative bias of the Wehnelt arm It with the point 22. The coating [9 is cylinder is taken from the steadying resistance connected with the point l4, and the coatings 5 f the main supply filter connection consisting of 0 and 2! with the points H and I2. 5 two condensers across the positive and the negaf now the switch is actuated, the wiper 16 at tive line, and between said condensers the named first enters into contact with the metallic coatresistance in the negative line, there usually ocg So that the Wehnelt cylinder is applied curs the case that the negative potential at the to the point I8.

Wehnelt cylinder takes efiect considerably more It is not until the wiper l3 has practically 10 slowly than the negative potential at the cathcomp eted its entire switch-on movement that ode, so that for a brief space of time the Wehnelt the wipe it passes from the coating 28 to the cylinder possesses a strong positive potential in coating 21, so that the Wehnelt cylinder is linked relation t the t up 7 with the steadying' resistance 4. In this If now the Braun tube is connected after quite manner it is accomplished that the negative bias. 15 a brief period of disconnection, in such fashion of the Wehnelt cylinder takes effect more quickly that the cathode is still warm when connection than that of the Cathode,

takes place, an extremely high momentary emise tWO eS m y a u al y be a a d sion occurs, which leads to destruction of the on the same shaft. It is also possible in place t b of the second switch to provide a simple change- The subject matter of the invention is a methover switch, which is actuated by the switch-on 0d and also different arrangements which enable device when the final position is reached. this fault to be safely avoided. As shown by Fig. 2, it is also possible during According to the invention means are prothe switching-on operation to connect in the vided, which safely ensure that the negative bias earth line 25 a highly ohmic resistance 23 by 25 at the Wehnelt cylinder takes effect at least means of the switch 24, and in this manner to equally as quickly as and preferably more quickly accelerate the charging of the Wehnelt cylinder.

than the cathode potential, in such a manner The resistance 23 may be selected, for example, that the Wehnelt cylinder at no time is able to at 10 Ohms, and'the switch 24 may be positivebecome more positive than the cathode. 13 upled with the switch l3, as described in 30 The invention will be best understood by refconjunction with Fig, 2. erence to the accompanying drawing 1-3, which As shown in Fig. 3, it is also possible to take certain forms of embodiment of the invention the bias for the Wehnelt cylinder not from the illustrate by way of example: steadying resistance 4, but from a special resist- In Fig. l, l is the rectifier tube, 2 and 3 are ance 26 situated between the steadying block 3 35 the steadying condensers, 4 is the steadying reand the cathode 6. In this case no further presistance, from which the negative bias for the cautions are required.

Wehnelt cylinder 7 is derived through the medi- The corresponding parts in Figs. 2 and 3 are um of a resistance 5, 6 the cathode, and 8 a condesignated in agreement with Fig. 1.

denser, through the medium of which the control The method according to the invention enables 40 potential, which is represented symbolically as the Braun tube to be switched on even after a generator 9, is conducted to the Wehnelt cylinshort period of disconnection without endangerder. !3 is the switch-on arrangement. ing the cathode.

According to the invention, there is provided I claim; a switch [8, which enables the Wehnelt cylinder 1, A t 1 vi 1 arrangement comprising a 45 to be linked up with the line H) in direct fashion Braun tube having a cathode, anode and conduring the switching-0n operat o in der n trol electrode, means energized from a commerthis manner to accompl sh that the negative b as cial power source for supplying direct current poat the same takes e f m q y than h tential to the electrodes of said Braun tube,

cathode potential. means for filtering the potential supplied to said 50 A form of embodiment of a switching arrangeelectrodes comprising two condensers connected ment necessary for this phrpOSe is i lustrated across the positive and negative conductors of the y y Of example in in which '3 a d direct current source and a resistance in the neg- Etre tWO W p Which are positively Coupled With ative conductor between said condensers, means each other by the lever 20 and 2| are for biasing said control electrode comprising a 55 connection to a point on said resistance, a first switching means for connecting the direct current source to the anode and cathode of the Braun tube, and a second switching means for directly connecting said control electrode to either the negative terminal of said direct current source, or to a point on said resistance, said first and second switching means being mechanically coupled whereby upon operation of said first switching means the control electrode is first connected to the negative terminal of the direct current source and is later connected to a point on said resistance.

2'. A television arrangement comprising a Braun tube having a cathode, anode and control electrode, means energized from a commercial power source for supplying direct current potential to the electrodes of said Braun tube, means for filtering the potential supplied to said electrodes comprising two condensers connected across the positive and negative conductors of the direct current source and two resistances in the negative conductor, the first between said condensers and the second between said cathode and said connection point of said first resistance and said second filtering condenser connected through said first resistance to the potential source, means for biasing, said control electrode comprising a connection to a point on said second resistance.

' 3. A television arrangement comprising a Braun tube having a cathode, anode and control electrode, means energized from a commercial power source for supplying direct current 'potential to the electrodes of said Braun tube,

means for filtering the potential supplied to said electrodes comprising two condensers connected across the positive and negative conductors of the direct current source and a resistance in the negative conductor between said condensers, means for biasing said control electrode comprising a connection to a point on said resistance, an intensity control potential source, a third condenser and a second highly ohmic resistance connected in series between said control electrode and said positive terminal of said direct current potential source, a first switching means for connecting the direct current source to the anode and cathode of the Braun tube and a second switching means for preliminarily connecting said highly ohmic resistance in series with said control potential source, said first and second switching means being mechanically coupled.

4. A television arrangement comprising a Braun tube having at least a cathode, anode, and control electrode, potential supply means energized from a commercial power source for supplying direct current potential to the electrodes of said Braun tube, means for filtering the potential supplied to said electrodes, comprising two condensers connected across the positive and negative conductors of the direct current source, and a resistance in the negative conductor between said condensers, means for biasing said control-electrode from a potential developed 7 across said resistance and means including said potential supply means and said filtering means I for preventing the control electrode from becoming positive with respect to said cathode during the operation period of said television arrangement.

5. A television arrangement comprising a Braun tube having at least a cathode, anode, and control electrode, means energized from a commercial power source for supplying direct current potential to the electrodes of said Braun tube, means for filtering the potential supplied to said electrodes, comprising two condensers connected across the positive and negative conductors of the direct current source, and a resistance in the negative conductor between said condensers, means for biasing said control-electrode from a potential developed across said resistance comprising connections from said control-electrode and said cathode to said resistance and negative conductor respectively, the time constant of said filtering means connected in said conductor between said direct current potential source and said control electrode being no greater than, preferably smaller than the time constant of said filtering means connected in said conductor between said direct current potential source and said cathode, whereby the control-electrode is prevented from becoming positive with respect to said cathode during the operation period of said television arrangement.

KURT SCI-ILESINGER. 

